Anesthesia needle guide



ANESTHESIA NEEDLE GUIDE Filed April 12, 1954 2 Sheets-Sheet l July 5, 1955 G. c. KOHL 2,712,314

ANESTHESIA NEEDLE GUIDE Filed April 12, 1954 2 Sheets-Sheet 2 INVENTOR. 654LD C. KOf/L M M {m A TFOE/VEJ S' United States Patent 2,712,314 ANESTHESIA NEEDLE GUIDE Gerald C. Kohl, Tacoma, Wash. Application April 12, 1*354, Scriai No. 422,2?8 12 Claims. (Cl. 128-415) This invention relates to a device permitting injection of anesthetics locally into the wall of a cavity within the human body, and in its presently disclosed form constitutes a means facilitating anesthetic injection of the pudendal nerves by access through the birth canal of a female in preparation for child delivery. The invention is herein illustratively described by reference to its presently preas devised for the specific application lastmentioned above; however, it will be evident to those skilled in the art that certain modifications and variations in the illustrated embodiment may be made without departing from the essential features involved.

block for that purpose may be effected by injecting the main trunk of the pudendal nerve subjacent to each lateral wall of the birth canal. However, suitable instruments for accomplishing this result in a fully acceptable and reliable manner heretofore have not been available. present invention enables this method of anesthetization to be carried out safely, reliably, easily and quickly by a practicing obstetrician.

A specific object of this invention is to provide a simple and effective means for guiding the point of a hollow anesthesia needle through the birth canal and to the correct location on a lateral wall thereof for injecting the main trunk of the beneath the ischial spine to enter Alcocks canal.

A more specific object is a guide means for the described purpose Which may be positioned with great accu racy by a simple technique of palpation, both the guide means itself and the palpation technique used for such positioning being the same for substantially all adult females, regardless of Wide variations in the anatomies of diiferent individuals.

Still a more specific object is such an anesthesia needle guide means which automatically limits the depth of penetration of the needle point in the birth canal wall, which protects adjacent tissues from accidental laceration during insertion of the needle to the point of injection, and which in the process of positioning of the guide means irons out or presses aside any gathers of membranous tissue which otherwise might interfere with or deflect the needle point during the actual injection.

Still another object is an instrument of the type described which is reversible in the sense that the same instrument may be used for injecting the left pudendal nerve trunk and also the right pudendal nerve trunk.

in the illustrated form of the invention'the novel anesthesia needle guide comprises an elongated retractor having a head portion formed with a recess in the tip thereof adapted to slide along the inside face of a doctors palpatory finger, in order to guide such headportion to the in operative position contacting the correct point on the lateral wall of the birth canal such that the point of the pudendal nerve trunk subjacent thereto.

As a further feature of the gauged depth.

These and other features, objects and advantages of the invent-ion will become more fully evident from the following description by reference to the accompanying drawings. It will be understood, however, that the principles of the invention are applicable to the injection cations, as Well changes and modifications with respect to the details of construction may be made for convenience or other reasons in the manufacture instrument.

Figure 1 is a side view of the novel anesthesia needle guide.

Figure 2 is a bottom View of the same.

Figure 3 is a perspective view of the guide.

Figures 4, 5, 6 L successive stages in the procedure for ancsthetizing by injection of a guide.

Referring to Figures 1, 2 and 3, the device illustrated comprises a retractor means 10 having a head portion 12 and a shank or handle portion 14. The retractor means serves as the supporting and positioning means for each of two needle guide members in the form of elongated open-end tubes 16 and 18, which in the two operative positions of the device (i. e. applied to the right and left walls of the birth canal respectively) serve alternately to guide the hollow anesthesia needle to the correct point of injection.

The retractor means head portion 12. is of generally concave-convex form, its base being joined to the end of the elongated shank portion 14 and its tip having a recess 12a which generally embraces the inside face of the doctors palpatory finger in a manner and for guiding purposes to be described hereinafter. Between the recessed tip and the base of the head portion 12 is a locating aperture 12!: of generally circular form and of a size just ample to permit the tip of the doctors palpatory finger to press against the ischial spine of the patient through such aperture in the operative position of the guide instrument, as will be more fully explained hereinafter.

The handle or shank portion 14 of the retractor means 10 is of a length and of a form permitting insertion of the retractor head portion 12 into the birth canal and advancing the same into operative position adjacent the ischial spine by manipulation of the instrument conveniently from outside the entrance to the vagina. When in operative position the outer ends of the guide tubes will project out of the vaginal orifice so as to facilitate insertion of an anesthesia needle through such tubes.

In the illustrated form of the device, the retractor shank portion 14 has a jog or offset 14a therein generally intermediate its ends, which offset is provided with two apertures supportingly receiving the respective needle guide tubes 16 and 18 in their mounted position on the retractor 10. In the example the two guide tubes are of upwardly arched or bowed form as viewed in Figure 1. The outer ends of these guide tubes are located near the butt end of the shank 14 and below such shank, as viewed in Figure l, and after passing through the apertures in the shank offset 14a follow upwardly arched and laterally divergent lines extending along the length of the shank to their distal ends mounted on the head portion 12 at respectively opposite sides of the locating aperture 12b therein. The distal ends of these guide tubes are so located in relation to the aperture 121; that proper positioning of the retractor head portion 12; in relation to the ischial spine places the distal end of one such guide tube in contact with the birth canal wall at a point just above the subjacent main trunk of the pudental nerve, as hereinafter more fully explained. Preferably the distal ends of the guide tubes 16 and 18 project through retaining apertures in the head portion l2 and a short distance beyond the opposite face of such head portion. The guide tube tips 16a and 13a projecting a short distance beyond the convex face of the retractor head portion will tend to press firmly against and produce some depression of the wall tissue with the instrument in operative position to insure that the anesthesia needle tip projected through the distal end openings will penetrate such tissue without a tendency to slide thereon.

In a practical design the guide tubes 16 and 18 have an internal diameter of about one millimeter and will be capable of receiving and guiding an elongated tubular anesthesia needle of approximately one-half millimeter or less outside diameter for the described purpose. Flexible tubular anesthesia injection needles of sufficient length to inject the pudental nerve trunks in the described manner by insertion through the guide tubes 16 and 18 are available. Obviously the guide tubes if of curved form as illustrated must be curved gently in order to avoid excessive bending of the anesthesia needle being inserted through such tubes. If the curvature of the guide tubes is moderate as shown, friction resistance to passage of the needle through either tube will not be sutficient to require use of lubricant. in the fully inserted position of the guide the head needle in a guide tube the needle tip should ordinarily project about one-half inch beyond the distal opening of such guide tube. Abutment of the hilt in the needle against the receiving end of the guide tube serves the gauging function of establishing the depth of penetration of the needle tip into the cavity wall tissue. The guide tubes 16 and 18 in the example are approximately five and one-half inches long, and an anesthesia needle used with such a device preferably would be approximately six inches in length. The locating aperture 1.2!; may vary somewhat in size and form, but in the example is about five-eighths of an inch in diameter and circular. The distal ends of the respective guide tubes are situated about seven-eighths of an inch apart and located on a transverse line which is approximately tangential to the forward or tip edge of the locating aperture 121). The purpose of bowing the guide tubes 16 and 18, as viewed in Figure 1 is to dispose the distal end portions of such tubes at a substantial incline to the birth canal wall area contacted by the head portion 12b, thereby insuring direct penetration of the needle tip to the required depth in the wall tissue as desired.

Referring to the sequence of operational views, Figures 4 through 7, the first step taken by the doctor in using the instrument is to locate the tip of the middle finger of one hand in contact with the spine of the ischium I, as shown in Figure 4. In this figure the fingertip T of the doctors left hand is placed in contact with the ischial spine I on the left side of the patient, with the palm of the hand facing toward the left thigh. Since the ischial spine is a bondy prominence very easily reached and located by palpation through the vagina, this initial step consumes very little time.

The second step, as shown in Figure 5, is to introduce the head portion of the instrument into the birth canal by sliding it first along the palm of the hand and then along the palpatory finger, using the tip recess 12a to portion 12 lengthwise along the face of the correct finger as the instrument is being inserted. For this purpose the convex side of the head portion 12 necessarily faces toward the left thigh of the patient. The shank or handle portion 14, is formed to be grasped in the doctors right hand in order to advance the instrument the necessary distance. In Figure 6 the relationship between the palpatory finger T and the recessed tip 12a during insertion of the instrument is illustrated with greater clarity.

During the insertion movement of the instrument the palpatory finger T remains in contact with the ischial spine I. When the recessed tip 12a reaches the point of contact, it necessarily wedges itself between the fingertip and the ischial spine. However, by holding the palpatory hand steady during further advance of the instrument the locating aperture 1212 will soon come into registry with the fingertip and the latter will be permitted to drop back into contact with the ischial spine I through the aperture 12b. The aperture 12b is of a sufficient size so that the ischial spine can readily be identified by palpation through such aperture with the instrument in the position shown in Figure 7, the operative position.

In the operative position of the instrument as shown in Figure 7, the bony prominence representing the ischial spine in effect serves as a locating element for the guide instrument, and it is found that when the locating aperture 12b of the instrument rests in registry with the ischial spine the distal opening of the lower guide tube (18a) in the example will, in practically all patients be correctly positioned to guide the projecting end of an anesthesia needle for injecting the pudental nerve trunk. In Figure 7 it will be noted that the guide instrument in its operative position may be held steady with the palpatory hand, which leaves the doctors other hand free for the purpose of inserting the anesthesia needle N into the correct guide tube (18) for injecting the pudental nerve. The lateral spacing of the two guide tubes intermediate their ends permits them to traddle or embrace the palpatory finger as an aid in steadying the instrument during insertion of the needle.

In order to inject the opposite side of the birth pudental nerve trunk on the canal to complete the anesthesia, the instrument is retracted, turned about its longitudinal axis through 180, and reinserted with the convex side of the retractor head portion 12 facing the right thigh of the patient. It is, of course, necessary for the doctor in this case to use his right hand as the palpatory hand and the left hand as the assist. case the guide tube i6 assumes the correct position for injecting the main trunk of right side of the birth canal.

From the above description it will be evident that the desired result of locating the distal end of a guide tube or equivalent guide member at the correct injection point palpable through the opening of a body cavity is accomplished by a locating element connected to the distal end are interconnected and supported by a retractor device having a shank portion extending throughout the length of the instrument and having a head portion interconof the respective tubes on the opposite lateral walls of the patients birth canal. However, the details or" construction may vary even for the illustrated application and may vary also for other applications of the invenuse as well as other usages which from a basic standpoint may include rectal, oral or incisional-cavity wall subadjacent nerve anesthetization.

I claim as my invention:

1. Anesthesia needle guide means comprising, in combination, retractor means having a head portion by said head portion.

2. Anesthesia needle guide means as defined in claim 1, wherein the guide member comprises a tube having its distal end secured to the retractor means head portion and its other end secured to the retractor means shank portion.

ber distal end in operative positional relationship relative to such cavity wall.

4. Anesthesia needle guide means as defined in claim 1, wherein the retractor means head portion has an opening therein olfset laterally from the distal end of the guide member and of a size and form to permit palpain comnerve ischial spine to enter Alcocks canal, said guide means comprising retractor means having a head portion and a shank portion joined to the base of said head portion for 8; The guide means defined in claim 7, wherein the eating opening in the retractor means head portion comprises an aperture in said head portion located generntermediately between the recessed tip and the base of said head portion.

9. The guide means defined in claim 8, wherein the and beyond such distal end, the opposite end of said guide tube having handle means associated therewith and being positioned accessibly for insertion of the needle into said guide tube exterlorly of the patient, and locating means connected to said distal end of said guide tube and formed to slidingly engage a palpatory finger of the doctor and to be pressed thereby into contact with the ischial spine of the patient in the inserted position of said needle guide tube.

11. Means for guiding an anesthesia needle into the birth canal of a patient for injecting the main trunk of the pudental nerve where the latter follows beneath the ischial spine to enter Alcocks canal on either lateral wall of the birth canal, said guide means comprising a pair of elongated needle guide tubes fixedly interconnected, extending in side-by-side relationship and of a length sufiicient for insertion thereof through the vagina to place the distal end of one such tube in contact with the lateral wall of the birth canal in operative position thereon for guiding an anesthesia needle to the pudental nerve trunk by insertion of such needle through the tube and beyond such distal end, the opposite end of said guide tubes having handle means associated therewith and being positioned accessibly for insertion of the needle into said guide tube exteriorly of the patient, and locating means mounted between the distal ends of said guide tubes and formed to slidingly engage a palpatory finger of the doctor and to be pressed thereby into contact with the, ischial spine on either lateral wall of the birth canal or the patient in the inserted position of said needle guide tubes and thereby locate the distal end of one guide tube or the other in operative position in relation to one lateral wall or the other of the birth canal.

12. The guide means defined in claim ll, wherein the locating means comprises a concave-convex member having a recessed tip formed to be guided for sliding along the palpatory finger and having an intermediately situated opening formed generally in the base of the cavity for application of the tip of such finger against the ischial spine through such opening, thereby to locate one of the guide tubes in its operative position.

No references cited. 

